渐变传输线及电磁缝隙结构的超宽带天线设计

Nonuniform transmission line and fan-electromagnetic bandgap structure of ultra-wideband antenna

为满足超宽带通信系统对天线小型化、抗干扰性能的要求，设计出一款基于非均匀传输线的平面网状扇形电磁缝隙结构的超宽带天线。依据非均匀传输线及电磁缝隙电路等效理论，推导出该天线的有效相位常数，总结出一种天线电路等效理论的分析方法。对该天线进行了设计、制作并加以测量。结果显示，天线在3～10GHz辐射特性基本保持一致；在3．10～15．78GHz回波损耗小于-10dB，增益大于4．4dBi；正面相距10cm的两天线隔离度S21小于-20dB，群时延基本在±1ns内。仿真与测试结果基本吻合，该天线满足超宽带系统的通信要求。

In this paper, compact printed MP-FEBG （meshed-planar fan electromagnetic bandgap） UWB （ultra-wide band） antenna with NTL （ nonuniform transmission line） is investigated and characterized numerically. Based on the circuit equivalent theory of NTL and EBG （ electromagnetic bandgap）, the effective phase constant of the antenna is deduced. According to the theory, UWB antenna is designed, processed and measured. Results indicate that the proposed antenna yields an impedance bandwidth of 3.10 ～ 15.78 GHz with return loss 〈 - 10 dB, gain 〉 4.4 dBi. Furthermore, good group delay and transmission characteristics can be achieved in the UWB band.